Door locks are commonly used to lock doors and restrict access or passage through the doors. Door locks may provide restricted entry through one or both sides of the door. Door locks typically lock only one side of the door while permitting unrestricted access through the other side of the door. However, it may be desirable to lock both sides of the door for some door lock applications. Examples of door locks include key entry, combination dial locks, electronic locks, pushbutton locks and various other locks.
Pushbutton locks are access control devices which are typically fully mechanical locks having mechanical pushbuttons for entering a combination to unlock the lock. Pushbutton locks operate when the correct buttons are pushed in the proper sequence and a turn knob is rotated. Pressing the correct buttons in the proper sequence enters an unlocking code into the pushbutton lock to permit the turn knob to open a door latch when the turn knob is rotated. The unlocking code or combination of the pushbutton locks can be modified as desired.
Pushbutton locks can provide advantages over other types of locks. For example, pushbutton locks do not require a key which can be duplicated or lost. Also, mechanical pushbutton locks do not require an electronic system to operate the lock or a power source for the electronic system, such as a battery.
Mechanical pushbutton locks have been used in a variety of applications. For example, mechanical pushbutton locks have been used to provide access control for public buildings, commercial buildings, industrial buildings and residential buildings. One type of application for pushbutton locks is a glass door having a stile which contains the glass. The pushbutton lock is mounted on the stile. However, door stiles for glass doors have become narrower. Accordingly, existing pushbutton locks may not be suitable for glass doors having a narrow stile.
Existing pushbutton locks have included a turn knob which is manually rotated after the proper code is entered via the pushbuttons to unlatch the lock. A turn knob may not be suitable for use as a handle to open the door once the latch is unlatched. Also, the latching mechanism requires rotational drive from rotational movement of the turn knob to unlatch the latch. Rotational drive of the door latch may not be suitable for all door lock applications.
Existing pushbutton door locks have included a rotational handle in place of the rotatable turn knob. The rotatable handles rotate similarly to the turn knob but may also be used to open the door once the pushbutton lock is unlocked. The rotatable door handles require two movements by the operator to open the door after the proper unlocking code has been entered through the pushbuttons. The door handle is first rotated in a plane parallel to the face of the door to retract the door latch into the door stile. Subsequently, the person opening the door must pull or push the door handle perpendicularly relative to the face of the door. Accordingly, pushbutton door locks can be improved.
It would be advantageous to improve existing pushbutton door locks by providing pushbutton door locks having a narrow width suitable for use with glass doors having a narrow door stile. It would also be advantageous to improve existing pushbutton door locks by eliminating the rotational drive of the turn knob or door handle to retract the door latch. Existing pushbutton door locks could be further improved by providing mechanisms which simplify opening the door, such as retracting the door latch and opening the door with a single movement of the door handle after the proper unlocking combination has been entered through the pushbuttons.
Existing pushbutton door locks have included a combination chamber which can be set to a specific unlocking code or combination. The unlocking code is entered into the combination chamber by pushing the correct buttons in proper sequence. However, existing combination chambers have been relatively complex and have required numerous parts. Existing combination chambers for pushbutton locks have been relatively large which results in a relatively large overall size of the pushbutton lock. For example, the pushbutton locks may be too wide for doors having narrow door stiles and may also extend to far outward from the face of the door. Existing pushbutton door locks which extend outward from the door face a relatively great distance may be said to have a "high profile." High profile door locks may not be suitable for all applications. For example, such high profile door locks may interfere with an additional door, such as a storm door, which may be positioned relatively close to the door containing the pushbutton lock.
Accordingly, it would be advantageous to improve pushbutton door locks by providing new pushbutton door locks having low profiles. It would also be advantageous to improve pushbutton door locks by providing new combination chambers which are simplified, easier to manufacture, less costly and which have relatively smaller sizes. Other advantages for having new pushbutton door locks will become apparent in view of the present invention.